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authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-08 14:51:05 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-08 14:51:05 -0400
commitebb37277796269da36a8bc5d72ed1e8e1fb7d34b (patch)
tree0ded627a62a5cec70b18d12825dd858855c135d3 /Documentation/ABI/testing
parent4de13d7aa8f4d02f4dc99d4609575659f92b3c5a (diff)
parentf50efd2fdbd9b35b11f5778ed85beb764184bda9 (diff)
Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe: "It might look big in volume, but when categorized, not a lot of drivers are touched. The pull request contains: - mtip32xx fixes from Micron. - A slew of drbd updates, this time in a nicer series. - bcache, a flash/ssd caching framework from Kent. - Fixes for cciss" * 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits) bcache: Use bd_link_disk_holder() bcache: Allocator cleanup/fixes cciss: bug fix to prevent cciss from loading in kdump crash kernel cciss: add cciss_allow_hpsa module parameter drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions mtip32xx: Workaround for unaligned writes bcache: Make sure blocksize isn't smaller than device blocksize bcache: Fix merge_bvec_fn usage for when it modifies the bvm bcache: Correctly check against BIO_MAX_PAGES bcache: Hack around stuff that clones up to bi_max_vecs bcache: Set ra_pages based on backing device's ra_pages bcache: Take data offset from the bdev superblock. mtip32xx: mtip32xx: Disable TRIM support mtip32xx: fix a smatch warning bcache: Disable broken btree fuzz tester bcache: Fix a format string overflow bcache: Fix a minor memory leak on device teardown bcache: Documentation updates bcache: Use WARN_ONCE() instead of __WARN() bcache: Add missing #include <linux/prefetch.h> ...
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1What: /sys/block/<disk>/bcache/unregister
2Date: November 2010
3Contact: Kent Overstreet <kent.overstreet@gmail.com>
4Description:
5 A write to this file causes the backing device or cache to be
6 unregistered. If a backing device had dirty data in the cache,
7 writeback mode is automatically disabled and all dirty data is
8 flushed before the device is unregistered. Caches unregister
9 all associated backing devices before unregistering themselves.
10
11What: /sys/block/<disk>/bcache/clear_stats
12Date: November 2010
13Contact: Kent Overstreet <kent.overstreet@gmail.com>
14Description:
15 Writing to this file resets all the statistics for the device.
16
17What: /sys/block/<disk>/bcache/cache
18Date: November 2010
19Contact: Kent Overstreet <kent.overstreet@gmail.com>
20Description:
21 For a backing device that has cache, a symlink to
22 the bcache/ dir of that cache.
23
24What: /sys/block/<disk>/bcache/cache_hits
25Date: November 2010
26Contact: Kent Overstreet <kent.overstreet@gmail.com>
27Description:
28 For backing devices: integer number of full cache hits,
29 counted per bio. A partial cache hit counts as a miss.
30
31What: /sys/block/<disk>/bcache/cache_misses
32Date: November 2010
33Contact: Kent Overstreet <kent.overstreet@gmail.com>
34Description:
35 For backing devices: integer number of cache misses.
36
37What: /sys/block/<disk>/bcache/cache_hit_ratio
38Date: November 2010
39Contact: Kent Overstreet <kent.overstreet@gmail.com>
40Description:
41 For backing devices: cache hits as a percentage.
42
43What: /sys/block/<disk>/bcache/sequential_cutoff
44Date: November 2010
45Contact: Kent Overstreet <kent.overstreet@gmail.com>
46Description:
47 For backing devices: Threshold past which sequential IO will
48 skip the cache. Read and written as bytes in human readable
49 units (i.e. echo 10M > sequntial_cutoff).
50
51What: /sys/block/<disk>/bcache/bypassed
52Date: November 2010
53Contact: Kent Overstreet <kent.overstreet@gmail.com>
54Description:
55 Sum of all reads and writes that have bypassed the cache (due
56 to the sequential cutoff). Expressed as bytes in human
57 readable units.
58
59What: /sys/block/<disk>/bcache/writeback
60Date: November 2010
61Contact: Kent Overstreet <kent.overstreet@gmail.com>
62Description:
63 For backing devices: When on, writeback caching is enabled and
64 writes will be buffered in the cache. When off, caching is in
65 writethrough mode; reads and writes will be added to the
66 cache but no write buffering will take place.
67
68What: /sys/block/<disk>/bcache/writeback_running
69Date: November 2010
70Contact: Kent Overstreet <kent.overstreet@gmail.com>
71Description:
72 For backing devices: when off, dirty data will not be written
73 from the cache to the backing device. The cache will still be
74 used to buffer writes until it is mostly full, at which point
75 writes transparently revert to writethrough mode. Intended only
76 for benchmarking/testing.
77
78What: /sys/block/<disk>/bcache/writeback_delay
79Date: November 2010
80Contact: Kent Overstreet <kent.overstreet@gmail.com>
81Description:
82 For backing devices: In writeback mode, when dirty data is
83 written to the cache and the cache held no dirty data for that
84 backing device, writeback from cache to backing device starts
85 after this delay, expressed as an integer number of seconds.
86
87What: /sys/block/<disk>/bcache/writeback_percent
88Date: November 2010
89Contact: Kent Overstreet <kent.overstreet@gmail.com>
90Description:
91 For backing devices: If nonzero, writeback from cache to
92 backing device only takes place when more than this percentage
93 of the cache is used, allowing more write coalescing to take
94 place and reducing total number of writes sent to the backing
95 device. Integer between 0 and 40.
96
97What: /sys/block/<disk>/bcache/synchronous
98Date: November 2010
99Contact: Kent Overstreet <kent.overstreet@gmail.com>
100Description:
101 For a cache, a boolean that allows synchronous mode to be
102 switched on and off. In synchronous mode all writes are ordered
103 such that the cache can reliably recover from unclean shutdown;
104 if disabled bcache will not generally wait for writes to
105 complete but if the cache is not shut down cleanly all data
106 will be discarded from the cache. Should not be turned off with
107 writeback caching enabled.
108
109What: /sys/block/<disk>/bcache/discard
110Date: November 2010
111Contact: Kent Overstreet <kent.overstreet@gmail.com>
112Description:
113 For a cache, a boolean allowing discard/TRIM to be turned off
114 or back on if the device supports it.
115
116What: /sys/block/<disk>/bcache/bucket_size
117Date: November 2010
118Contact: Kent Overstreet <kent.overstreet@gmail.com>
119Description:
120 For a cache, bucket size in human readable units, as set at
121 cache creation time; should match the erase block size of the
122 SSD for optimal performance.
123
124What: /sys/block/<disk>/bcache/nbuckets
125Date: November 2010
126Contact: Kent Overstreet <kent.overstreet@gmail.com>
127Description:
128 For a cache, the number of usable buckets.
129
130What: /sys/block/<disk>/bcache/tree_depth
131Date: November 2010
132Contact: Kent Overstreet <kent.overstreet@gmail.com>
133Description:
134 For a cache, height of the btree excluding leaf nodes (i.e. a
135 one node tree will have a depth of 0).
136
137What: /sys/block/<disk>/bcache/btree_cache_size
138Date: November 2010
139Contact: Kent Overstreet <kent.overstreet@gmail.com>
140Description:
141 Number of btree buckets/nodes that are currently cached in
142 memory; cache dynamically grows and shrinks in response to
143 memory pressure from the rest of the system.
144
145What: /sys/block/<disk>/bcache/written
146Date: November 2010
147Contact: Kent Overstreet <kent.overstreet@gmail.com>
148Description:
149 For a cache, total amount of data in human readable units
150 written to the cache, excluding all metadata.
151
152What: /sys/block/<disk>/bcache/btree_written
153Date: November 2010
154Contact: Kent Overstreet <kent.overstreet@gmail.com>
155Description:
156 For a cache, sum of all btree writes in human readable units.